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Prof. Andrew Beale discusses our recently published paper on 5D diffraction imaging in his Behind the Paper article – Chemistry in multiple dimensions

3D image for chemistry in multiple dimensionsSolid catalysts are used in almost every field of the chemical industry, ranging from pharmaceuticals to petrochemicals as well as the automotive industry, to produce the desired products. These catalytic solids usually comprise complex 3D structures which can be inhomogeneous. In recent years, it has been realised that it is crucial to investigate these materials using characterisation techniques that provide spatially-resolved information as these heterogeneities can play a crucial role in the catalyst performance.

In our recent paper in Nature Communications we show that synchrotron X-ray diffraction computed tomography (XRD-CT) can be used to study the evolution in solid-state composition in complex materials in 3D under real process conditions and as a function of time; specifically a complex multi-component Ni-Pd/CeO2-ZrO2/Al2O3 solid catalyst under operating conditions.

Read the full article at https://chemistrycommunity.nature.com/channels/1465-behind-the-paper/posts/40955-5d-chemical-imaging

5D operando tomographic diffraction imaging of a catalyst bed

Our paper on 5D operando tomographic diffraction imaging of a catalyst bed has been published online by Nature Communications, volume 9, Article number: 4751 (2018)

We report the results from the first 5D tomographic diffraction imaging experiment of a complex Ni–Pd/CeO2–ZrO2/Al2O3 catalyst used for methane reforming. This five-dimensional (three spatial, one scattering and one dimension to denote time/imposed state) approach enabled us to track the chemical evolution of many particles across the catalyst bed and relate these changes to the gas environment that the particles experience. Rietveld analysis of some 2 × 106 diffraction patterns allowed us to extract heterogeneities in the catalyst from the Å to the nm and to the μm scale (3D maps corresponding to unit cell lattice parameters, crystallite sizes and phase distribution maps respectively) under different chemical environments. We are able to capture the evolution of the Ni-containing species and gain a more complete insight into the multiple roles of the CeO2-ZrO2 promoters and the reasons behind the partial deactivation of the catalyst during partial oxidation of methane.

Read the full article at https://doi.org/10.1038/s41467-018-07046-8